WO2016078538A1

WO2016078538A1 - Common rail assembly, urea injection system and application thereof

Info

Publication number: WO2016078538A1
Application number: PCT/CN2015/094449
Authority: WO
Inventors: 杨振球; 龚超; 樊高峰; 刘大玲; 张海涛; 吴安舟; 管帅
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2014-11-21
Filing date: 2015-11-12
Publication date: 2016-05-26
Also published as: EP3228839A1; US20170328260A1; EP3228839A4; EP3228839B1; US10202883B2

Abstract

A common rail assembly used in a urea injection system (100), comprising at least a first common rail (51) and a second common rail (52) which are connected to each other, wherein the first common rail (51) comprises a first housing (511), a pressure detecting device (512) mounted on the first housing (511) and a pressure adjusting device (513). The first housing (511) comprises a first urea inlet channel (5141), a first urea outlet channel (5151), at least one first feeding inlet (5142) connected to the first urea inlet channel (5141) and at least one first back-flow outlet (5152) connected to the first urea outlet channel (5151). The pressure detecting device (512) is connected to the first urea inlet channel (5141). The pressure adjusting device (513) can connect/disconnect the first urea inlet channel (5141) to/from the first urea outlet channel (5151). Also disclosed are a urea injection system and the application of the common rail assembly. A proper number of common rails selected based on different application requirements can be combined together by at least connecting the first common rail to the second common rail in series. The extension capability thereof is relatively high.

Description

Common rail assembly, urea injection system and its application

Technical field

The invention relates to a common rail assembly, a urea injection system and an application thereof, and belongs to the technical field of engine exhaust aftertreatment.

Background technique

The application of the common rail system in the fuel injection system of the engine has been around for a long time. This common structure of fuel injection is very limited in its structure because it needs to withstand very high pressures. Since the cylindrical structure can withstand higher pressure than other structures, the common rail of the existing fuel injection almost adopts a cylindrical structure.

As countries' emission standards become more stringent, higher requirements are imposed on urea injection systems as tail gas treatment. How to control the pressure in the urea injection system has become a common technical problem in the industry.

In addition, especially for the exhaust gas treatment of high-power engines, the piping of the urea injection system tends to be long and the pressure loss is relatively large. Therefore, it is necessary to provide a common rail capable of stabilizing the system pressure, the application of the common rail, and the common rail. Urea injection system.

In addition, when the common rail is used in a large engine aftertreatment system, in order to meet different design requirements, it is often necessary to design a common rail that matches it, and this solution greatly increases the cost.

Therefore, it is necessary to design a new common rail assembly based on combining several common rails to solve the above problems.

Summary of the invention

It is an object of the present invention to provide a common rail assembly, urea injection system and applications thereof that have a high expansion capability.

To achieve the above object, the present invention adopts the following technical solution: a common rail assembly for use in a urea injection system, the common rail assembly including at least a first common rail and a second common rail interconnected, wherein the first The common rail includes a first housing, a pressure detecting device mounted on the first housing, and a pressure regulating device; the first housing includes a first urea inlet passage for entering a urea solution for supplying urea a first urea outlet passage through which the solution flows, at least one first delivery port connected to the first urea inlet passage, and at least one first return port connected to the first urea outlet passage; the pressure detecting device The first urea inlet passage is connected; the pressure regulating device is connected between the first urea inlet passage and the first urea outlet passage, a pressure regulating device capable of communicating or intercepting the first urea inlet passage with the first urea outlet passage; the second common rail includes a second housing, the second housing including the first urea inlet a second urea inlet passage communicating with the passage, a second urea outlet passage communicating with the first urea outlet passage, at least one second delivery port connected to the second urea inlet passage, and the second urea outlet passage At least one second return port connected.

As a further improvement of the present invention, the first housing is substantially a rectangular parallelepiped, and includes a first end surface, a second end surface, a third end surface, and a fourth end surface, wherein the first end surface is opposite to the second end surface The third end surface is opposite to the fourth end surface; the first urea inlet passage and the first urea outlet passage penetrate the first end surface and/or the second end surface, the first conveying port The first return port penetrates the fourth end surface through the third end surface.

As a further improvement of the technical solution of the present invention, the first conveying port is provided, and the first common rail is provided with a first conveying joint connected to each of the first conveying ports; the first returning port is a plurality of The first common rail is provided with a first return joint connected to each of the first return ports; wherein the number of the first return joints is the same as the number of the first transfer joints.

As a further improvement of the present invention, the first conveying joint is spaced between the first end surface and the second end surface, and the first reflow joint is also spaced apart from the first end surface and the Between the second end faces, the first delivery joint is opposite to the first return joint, and each of the first delivery ports is aligned with the corresponding first return port.

As a further improvement of the invention, a urea mass sensor is mounted on the at least one first delivery joint.

As a further improved technical solution of the present invention, the first urea inlet passage and the first urea outlet passage are parallel to each other, the first conveying joint is perpendicular to the first urea inlet passage, and the return joint is perpendicular to the The first urea outlet passage is described.

As a further improved technical solution of the present invention, the common rail assembly includes a first connecting pipe connecting the first urea inlet passage and the second urea inlet passage, and connecting the first urea outlet passage and the first a second connecting pipe of the diurea outlet passage.

As a further improved technical solution of the present invention, the first housing further includes a front surface perpendicular to the first, second, third, and fourth end faces and a back surface opposite to the front surface, wherein the front surface Mounting holes through the back are opened in all four corners.

As a further improved technical solution of the present invention, the first housing further includes a front surface perpendicular to the first, second, third, and fourth end faces and a back surface opposite to the front surface, wherein the back surface is There is a mounting groove for mounting the pressure regulating device.

As a further improved technical solution of the present invention, the pressure regulating device is a pressure control valve, and when the pressure sensor detects that the pressure is greater than a set value, the pressure control valve is opened.

The present invention also relates to a urea injection system for treating exhaust gas of an engine, the urea injection system comprising a urea tank, a fluid delivery device for extracting the urea solution in the urea tank outward, and the fluid delivery a common rail assembly coupled to the apparatus, a nozzle coupled to the common rail assembly, and a controller for controlling the urea injection system, the fluid delivery device including a pump for extracting a urea solution, the common rail assembly being A common rail assembly, wherein the nozzle is in communication with the first delivery port.

The invention also relates to the use of the above common rail in a diesel engine exhaust gas treatment system with a power exceeding 500 kW.

Compared with the prior art, the first common rail of the present invention is provided with a first urea inlet passage for the urea solution to enter and a first urea outlet passage for the urea solution to flow out, the pressure regulating device capable of The first urea inlet passage is connected or disconnected from the first urea outlet passage to adjust the system pressure; in addition, by connecting at least the first common rail and the second common rail, an appropriate number of totals can be selected according to different application requirements. The track is combined and the expansion capability is strong.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a urea injection system for engine exhaust gas treatment of the present invention.

Figure 2 is a perspective view of the common rail assembly of Figure 1.

Figure 3 is a plan view of Figure 2.

Fig. 4 is a bottom view of Fig. 2;

Figure 5 is a cross-sectional view of the common rail assembly of the present invention at a certain location.

Figure 6 is a partial exploded view of Figure 2.

Figure 7 is an exploded perspective view of the first common rail of Figure 2;

Figure 8 is a cross-sectional view of the first common rail of Figure 2.

detailed description

Referring to FIG. 1, the present invention discloses a urea injection system 100 that can be applied to exhaust gas aftertreatment of a large engine. The urea injection system 100 includes a urea tank 1 and a filter group connected to the urea tank 1. a fluid transport device 4 for transporting the urea solution, a common rail assembly 5 connected to the fluid transport device 4, a plurality of nozzles 6 connected to the common rail assembly 5, and a unit for controlling the urea injection Controller 2 of system 100.

In the illustrated embodiment of the invention, the engine 200 is a high power engine that typically exceeds 500 kilowatts. The fluid delivery device 4 is provided with a pump 41 (for example a gear pump or the like) for pumping a urea solution. In the illustrated embodiment of the invention, the controller 2 is mounted on the fluid delivery device 4 for integration. The nozzle 6 is used to inject an atomized urea solution into the engine exhaust pipe 201. The atomized urea solution is decomposed into ammonia gas in the engine exhaust pipe 201, and the ammonia gas can react with nitrogen oxides in the exhaust gas, thereby reducing nitrogen oxide emissions. In view of the fact that the principles of such exhaust gas treatment techniques are well known to those skilled in the art, the invention is not described herein.

Referring to FIG. 2 to FIG. 8 , in the illustrated embodiment of the present invention, the common rail assembly 5 includes a first common rail 51 , a second common rail 52 , and a third common rail 53 , which are connected in series. Four common rails 54 and a fifth common rail 55. The structures of the second, third, fourth, and fifth

common rails

52, 53, 54, 54 are the same, and the structures of the first common rail 51 and the second common rail 52 are very similar, so as to facilitate Share equipment/mold to save manufacturing costs. The following is only a detailed description of the first common rail 51 as an example.

Referring to Figures 19 and 20, the first common rail 51 is used to regulate the pressure in the urea injection system 100. Specifically, the first common rail 51 includes a first housing 511, a pressure detecting device 512 mounted on the first housing 511, and a pressure adjusting device 513. The first housing 511 is substantially rectangular parallelepiped, and includes a first end surface 5111, a second end surface 5122, a third end surface 5113, a fourth end surface 5114, a front surface 5115, and a back surface 5116 opposite to the front surface 5115 (refer to FIG. 4 Show). The first end surface 5111 is opposite to the second end surface 5112; the third end surface 5113 is opposite to the fourth end surface 5114; the front surface 5115 and the first end surface 5111, the second end surface 5122, The three end faces 5113 and the fourth end face 5114 are both perpendicular. The four corners of the front surface 5115 are each provided with a mounting hole 5117 (shown in FIG. 8) for mounting and fixing the first common rail 51 to a predetermined position. The back surface 5116 is provided with a mounting groove 5118 for mounting the pressure adjusting device 513.

The first housing 511 further includes a first urea inlet passage 5141 for entering the urea solution, a first urea outlet passage 5151 for the urea solution to flow out, and a plurality of the first urea inlet passage 5141. A delivery port 5142 and a plurality of first return ports 5152 connected to the first urea outlet channel 5151. The first urea inlet channel 5141 and the first urea outlet channel 5151 extend through the first end surface 5111 and/or the second end surface 5112. In the illustrated embodiment of the invention, the first urea inlet channel 5141 is as described The first urea outlet passages 5151 each penetrate the first end surface 5111. The first urea inlet passage 5141 and the first urea outlet passage 5151 are parallel to each other to facilitate processing. In the illustrated embodiment of the present invention, the third end surface 5113 is provided with three first delivery ports 5142 and three first delivery joints 5143 connected to the first delivery port 5142. Each of the first delivery joints 5143 is perpendicular to the first urea inlet passage 5141. The three first conveying joints 5143 are spaced apart between the first end surface 5111 and the second end surface 5112. In the illustrated embodiment of the invention, a urea mass sensor 516 is mounted on the first delivery joint 5143 adjacent the third end face 5113. Of course, in other embodiments, the urea mass sensor 516 can also be mounted on any one of the first delivery joints 5143; or all of the three first delivery joints 5143 can be mounted with a urea mass sensor 516.

In the illustrated embodiment of the present invention, the first return port 5152 is also three, three first return ports 5152 and three connected to the first return port 5152 are disposed on the fourth end face 5114. The first return joint 5153. Each of the first return connections 5153 is perpendicular to the first urea outlet passage 5151. The three first return joints 5153 are also spaced apart between the first end face 5111 and the second end face 5112. The first delivery port 5142 extends through the third end surface 5113 , and the first return port 5152 extends through the fourth end surface 5114 . The number of the first return joints 5153 is the same as the number of the first transfer joints 5143, but the mounting direction is opposite. Each of the first delivery ports 5142 is aligned with the corresponding first return port 5152.

In the illustrated embodiment of the invention, the pressure sensing device 512 is a pressure sensor mounted on the second end face 5112 and in communication with the first urea inlet passage 5141. In the illustrated embodiment of the invention, the pressure regulating device 512 is a pressure control valve that is mounted in the mounting groove 5118. So as to be functionally, the pressure control valve is connected between the first urea inlet passage 5141 and the first urea outlet passage 5151, and the pressure control valve can connect the first urea inlet passage 5141 is in communication with or disconnected from the first urea outlet passage 5151. For example, when the pressure sensor detects that the pressure in the first urea inlet passage 5141 is greater than a set value, the controller 2 opens the pressure control valve to achieve a pressure relief function.

The first common rail 51 of the present invention is very different from the common rail of the existing fuel injection. First, after extensive data analysis, the pressure applied to the common rail of the present invention in the urea injection system 100 is much less than the common rail of the fuel injection. Based on this analysis, the rectangular first casing 511 disclosed in the present invention has good workability. More importantly, this provides a solution for integrating the first urea outlet passage 5151 in the first common rail 51. Of course, in the illustrated embodiment of the invention, the diameter of the first urea inlet channel 5141 It is larger than the diameter of the first urea outlet passage 5151. The reason for this design is that, by scientific analysis, it is found that the pressure required to be withstood by the first urea inlet passage 5141 and the first urea outlet passage 5151 is also different.

The second common rail 52 is very similar to the structure of the first common rail 51 and is briefly described as follows.

The second common rail 52 includes a second housing 521 including a second urea inlet passage 5241 communicating with the first urea inlet passage 5141 and communicating with the first urea outlet passage 5151 a second urea outlet channel 5251, a plurality of second delivery ports 5242 connected to the second urea inlet channel 5241, and a plurality of second return ports 5252 connected to the second urea outlet channel 5251.

In addition, the common rail assembly 5 further includes a first connecting pipe 517 connecting the first urea inlet passage 5141 and the second urea inlet passage 5241, and connecting the first urea outlet passage 5241 and the second A second connecting tube 518 of the urea outlet channel 5251. The first connecting pipe 517 and the second connecting pipe 518 are both hollow pipes to realize the flow of the urea solution in the first common rail 51 and the second common rail.

It can be understood that the present invention includes a plurality of first connecting tubes 517 and a plurality of second connecting tubes 518 for the first common rail 51, the second common rail 52, the third common rail 53, the fourth common rail 54, and the fifth The common rails 55 are all connected in series. With this setting, it is possible to select a suitable number of common rails for combination according to different application requirements, and the expansion capability is strong.

In addition, the pressure control valve mounted on the first common rail 51 has three functions: first, assisting in establishing pressure in the urea pipeline; second, pressure regulation after pressure establishment; third, in the urea Before the injection system 100 is stopped, the air in the urea tank 1 is drawn into the line of the urea injection system by means of the reverse rotation of the pump 41 to evacuate the urea solution in the line.

Specifically, when the system is just beginning to establish pressure, there may be a large amount of air in the pipeline, and the compressibility of the air easily causes the failure of the build-up. The pressure control valve designed by the present invention skillfully solves such problems. The controller 2 controls to open the pressure control valve (for example, to bring the pressure control valve to a certain fixed opening or a varying opening) when the system first begins to build pressure, and the first urea inlet passage is 5141 communicates with the first urea outlet passage 5151 to provide a passage to release air in the pipeline to facilitate rapid pressure build-up of the pipeline.

After the system is completed, in order to ensure that the urea pressure in the first common rail 51 is maintained at a set pressure and is substantially constant, the controller 2 quickly adjusts the opening of the pressure control valve to pass The reflux flow of the urea solution is controlled to achieve the purpose of regulating the pressure.

Before the urea injection system 100 is stopped, the controller 2 opens the pressure control valve, and the pump 41 rotates in the reverse direction to draw the air in the urea tank 1 into the pipeline of the urea injection system. Evacuation The urea solution in the pipeline. It should be noted that before the urea injection system 100 is stopped, it means that the controller 2 has received a signal that the system is about to stop, at which time the nozzle 6 has stopped spraying, but the pump 41 is still rotating (for example Reverse). The urea solution in the pipeline is evacuated for the purpose of preventing damage to the system due to freezing and expansion of the urea solution.

In the illustrated embodiment of the invention, the nozzles 6 corresponding to each common rail are arranged in three. Each of the nozzles 6 is provided with a delivery line 61 communicating with a corresponding delivery port and a return line 62 communicating with a corresponding return port. In this way, on the one hand, the nozzle 6 can inject a urea solution into the exhaust pipe 201 for chemical reaction; on the other hand, the nozzle 6 can be cooled by a refluxing urea solution. The refluxed urea solution is first collected into the corresponding common rail through the return line 62, and then uniformly returned to the urea tank 1 through the return line 300. In the prior art, a scheme of directly introducing the return line 62 into the urea tank 1 is generally employed. This solution requires a separate return line 62 for each nozzle 6, which is costly. In addition, in combination with the application of the present invention, particularly in the exhaust gas treatment system of a high-power engine, the length of the pipeline between the urea tank 1 and the nozzle 6 tends to be large, and the existing reflow design cannot meet the requirements. .

In addition, the above embodiments are only for explaining the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present specification should be based on those skilled in the art, for example, "front and rear through" means that other parts are not installed. It has been exemplified before, for example, directional descriptions of "front", "back", "left", "right", "upper", "lower", etc., although the present specification has been carried out with reference to the above embodiments. DETAILED DESCRIPTION OF THE INVENTION However, those skilled in the art should understand that the invention may be modified or equivalently replaced by those skilled in the art without departing from the spirit and scope of the invention. It is intended to be included within the scope of the appended claims.

Claims

A common rail assembly for use in a urea injection system, characterized in that the common rail assembly comprises at least a first common rail and a second common rail interconnected, wherein the first common rail comprises a first housing, mounted on a pressure detecting device and a pressure regulating device on the first casing; the first casing includes a first urea inlet passage for entering the urea solution, a first urea outlet passage for the urea solution to flow out, and At least one first delivery port connected to the first urea inlet channel and at least one first return port connected to the first urea outlet channel; the pressure detecting device is connected to the first urea inlet channel; a pressure regulating device is coupled between the first urea inlet passage and the first urea outlet passage, the pressure regulating device capable of connecting or cutting the first urea inlet passage with the first urea outlet passage; The second common rail includes a second housing including a second urea inlet passage in communication with the first urea inlet passage, and the first urea outlet Urea second outlet channel communicating passage, the at least one second delivery port and said second inlet passage is connected to the urea and the at least one second return opening with said second outlet passage is connected to the urea.
The common rail assembly of claim 1 wherein said first housing is substantially rectangular parallelepiped and includes a first end surface, a second end surface, a third end surface, and a fourth end surface, wherein said first end surface is The second end surface is oppositely disposed, and the third end surface is opposite to the fourth end surface; the first urea inlet passage and the first urea outlet passage penetrate the first end surface and/or the second end surface, The first conveying port penetrates the third end surface, and the first return port penetrates the fourth end surface.
A common rail assembly according to claim 2, wherein said first plurality of delivery ports are provided, and said first common rail is provided with a first delivery joint connected to each of said first delivery ports; said A plurality of return ports are provided, and the first common rail is provided with a first return joint connected to each of the first return ports; wherein the number of the first return joints is the same as the number of the first transfer joints.
A common rail assembly according to claim 3, wherein said first delivery joint is spaced between said first end surface and said second end surface, said first reflow joints being also spaced apart in said Between the first end surface and the second end surface, the first conveying joint is opposite to the first return joint, and each of the first conveying ports is disposed in alignment with the corresponding first return port.
A common rail assembly according to claim 3 wherein a urea mass sensor is mounted on at least one of the first delivery joints.
A common rail assembly according to claim 2, wherein said first urea inlet passage and said first urea outlet passage are parallel to each other, said first delivery joint being perpendicular to said first urea inlet passage, The return joint is perpendicular to the first urea outlet passage.
A common rail assembly according to claim 1, wherein said common rail assembly includes a first connecting pipe connecting said first urea inlet passage and said second urea inlet passage, and connecting said first urea a second connecting tube of the outlet passage and the second urea outlet passage.
A common rail assembly according to claim 2, wherein said first housing further includes a front surface that is perpendicular to said first, second, third, and fourth end faces and a back surface that is opposite said front face Wherein the four corners of the front surface are provided with mounting holes penetrating the back surface.
A common rail assembly according to claim 2, wherein said first housing further includes a front surface that is perpendicular to said first, second, third, and fourth end faces and a back surface that is opposite said front face Wherein the back surface is provided with a mounting groove for mounting the pressure regulating device.
A common rail assembly according to claim 9, wherein said pressure regulating means is a pressure control valve, said pressure control valve being opened when said pressure sensor detects that the pressure is greater than a set value.
A urea injection system for treating exhaust gas of an engine, the urea injection system comprising a urea tank, a fluid delivery device for extracting the urea solution in the urea tank outward, and a total of the fluid delivery device a rail assembly, a nozzle coupled to the common rail assembly, and a controller for controlling the urea injection system, the fluid delivery device including a pump for extracting a urea solution, the common rail assembly being the claims 1 to 10 The common rail assembly of any of the preceding claims, wherein the nozzle is in communication with the first delivery port.
A common rail assembly for use in a diesel engine exhaust aftertreatment system having a power of more than 500 kW, characterized in that the common rail assembly is the common rail assembly of any one of claims 1 to 10.